Hi Jitendra, When we use bdev_nvme_attach_controller with multipath="failover", I/O path is recovered but I/O is failed immediately if I/O path error occurred. Will you try using bdev_nvme_attach_controller with multipath="multipath"? Please keep opts->bdev_retry_count to be -1 as you did. P.S., multipath="multipath" is still under development, and your experiment is very appreaciated if possible. Thanks, Shuhei ________________________________ 差出人: lullajd(a)yahoo.com <lullajd(a)yahoo.com&gt; 送信日時: 2021年11月12日 14:06 宛先: spdk(a)lists.01.org <spdk(a)lists.01.org&gt; 件名: [SPDK] appropriate timeout values in bdev_nvme_set_options for failover tests Hi, This is about the case where initiator is using spdk. For testing nvmeof/TCP failover (cold primary/backup) I am trying to use the following timeout values but they don't seem to help: { "subsystems": [ { "subsystem": "bdev", "config": [ { "method": "bdev_nvme_set_options", "params": { "retry_count": 254, "timeout_us": 255000000, "keep_alive_timeout_ms": 255000, "transport_retry_count": 254, "bdev_retry_count": -1, "nvme_adminq_poll_period_us": 100000, "nvme_ioq_poll_period_us": 0, In my test, when the IO has started, after some time, I am making the primary network path to the nvme device (nvmeof + tcp) unavailable. I expect the secondary path to become active and the IO must resume. Without spdk (ie when I use the kernel drivers on linux), the path switchover on initiator takes ~45 seconds and the IO resumes. I suspect something wrong in the timeout values above when trying with spdk. Could somebody please suggest more appropriate values for the above timeouts? And also please point out if something else also need to be corrected above? thanks Jitendra _______________________________________________ SPDK mailing list -- spdk(a)lists.01.org To unsubscribe send an email to spdk-leave(a)lists.01.org